epq课程对申请真的有用吗？Alevel加分的高人气选项
近几年，随着英本申请越来越“卷”，很多学生除了铆足劲提升学术成绩，还把目光转向了学术背景的提升。于是，EPQ项目就成为了家长和学生眼中的“最优选项”。epq课程对申请真的有用吗？一起来看看吧。 以往，一部分同...
Edexcel A Level Chemistry:复习笔记3.3.5 Saturation Test
Saturation Test Halogens can be used to test if a molecule is?unsaturated?(i.e. contains a double bond) Br2(aq) is an orange or yellow solution, called?bromine water?and this is the halogen ...
Edexcel A Level Chemistry:复习笔记3.3.4 Electrophilic Addition Mechanism
Electrophilic Addition Mechanism Electrophilic addition of hydrogen halides Hydrogen halides such as hydrogen bromide (HBr) are polar as the hydrogen and halogen atoms have different electro...
Edexcel A Level Chemistry:复习笔记3.3.3 Electrophilic Addition
Electrophilic Addition The double bond in alkenes is an area of high electron density (there are four electrons found in this double bond) This makes the double bond susceptible to attack by...
Edexcel A Level Chemistry:复习笔记3.3.2 Bonding in Alkenes
Bonding in Alkenes Each carbon atom has four electrons in its outer shell (electronic configuration: 1s22s22p2) Carbon atoms share these four electrons in four covalent bonds with other atom...
Edexcel A Level Chemistry:复习笔记3.3.1 Describing Alkenes
Describing Alkenes All alkenes contain a?double carbon bond, which is shown as two lines between two of the carbon atoms i.e. C=C All alkenes contain a double carbon bond, which is the funct...
Edexcel A Level Chemistry:复习笔记3.2.5 Free Radicals
Free Radical Substitution of Alkanes Alkanes can undergo?free-radical substitution?in which a hydrogen atom gets?substituted?by a halogen (chlorine / bromine) Since alkanes are very unreacti...
Edexcel A Level Chemistry:复习笔记3.2.4 Reducing Pollution
Catalytic Converters To reduce the amount of pollutants released in car exhaust fumes, many cars are now fitted with?catalytic converters Precious metals (such as platinum) are coated on a h...
Edexcel A Level Chemistry:复习笔记3.2.3 Pollution from Combustion
Causes & Effects of Pollution Alkanes are?combusted?(burnt) on a large scale for their use as fuels Complete combustion When alkanes are burnt in?excess?(plenty of) oxygen,?complete comb...
